Collection and description of the maize (Zea mays L.) germplasm complexes of Mexico began in 1943, and efforts toward the potential utilization of the 25 recognized Mexican races were initiated in 1961. This study was conducted to determine the performance of the 25 Mexican races and 300 interracial crosses evaluated in three environments identified as high (2249 m), intermediate (1800 m), and low (1300 m) elevations. Data were analyzed with the Gardner‐Eberhart model, Analysis II. At the high elevation the races Cónico, Cónico Norteño, and Chalqueño had high mean yields per se and in crosses. Cacahuacintle and Maiz Dulce had equally high yield in crosses but had lower per se yield. At the intermediate elevation, the best yielding races in crosses and per se were Comiteco, Harinoso de Ocho, Celaya, Maiz Dulce, Tabloncillo, and Tuxpeno. At the low elevation, the highest per se yields were exhibited by Harinoso de Ocho, Celaya, Pepitilla, and Tabloncillo. Across all elevations, the best general combiners were Cacahuacintle, Harinoso de Ocho, and Maiz Dulce. Results of this study could be used to (i) introgress the heterotic patterns found among races into new commercial varieties or populations, (ii) search for race collections with better agronomic type that belong to the racial heterotic pattern, (iii) improve gene pools based on racial heterotic patterns and geographical origins, (iv) establish reciprocal recurrent selection between two races that exhibited heterosis when crossed, or (v) develop hybrids based on lines derived from the collections studied in each environment.

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Gencbank accessions are a potential source of genetic variability for maize (Zea mays L.) breeding programs. Identification of useful individual entries is commonly based on the expression of one or more attributes in different sites or environments. This study was motivated by the need to identify a subset of Caribbean accessions for introgression in to elite germplasm of the western Corn Belt. Thus the objective was to identify potentially useful Caribbean accessions, based on (i) simultaneous consideration of six agronomic attributes deemed economically important for the western Corn Belt, and (ii) response patterns observed across four sharply contrasting environments. Both (i) and (ii) were addressed by means of three‐mode principal component analysis (PCA) of data on six agronomic and morphological attributes for 184 Caribbean maize accessions evaluated at four environments. Three‐way data were analyzed by three‐mode PCA and based on (i) and (ii), two joint plots were generated. From the PCA and joint plots, two subsets of accessions were identified. First, a subset of 14 accessions having body yield, intermediate plant height, and average days to anthesis was identified. Secondly, a subset of 10 accessions having average performance over all environments was identified. Two accessions were common to both subsets. Jointly, the two approaches produced a combined subset of 22 accessions, representing 12% of the total evaluated, and including representatives of 11 maize races. Three‐mode PCA integrated information on accessions, attributes, and environments, and provided a means of simultaneously visualizing these three types of information. Three‐mode PCA can complement standard methodologies used by plant breeders for identification of potentially useful accessions in introgression programs.